The present invention relates to impulse radio synchronization. Specifically, the present invention includes a system and method for impulse radio synchronization including an algorithm for achieving low average power consumption in the receiver. The present invention is primarily directed to applications of communication systems based on non-continuous transmission, e.g. impulse when the time interval between transmissions is predictable. Moreover, the present invention enables reception of more than one packet at the same times.
Impulse radio systems feature a transmitter that sends packets at times unknown to the receiver. Each packet includes:
(a) a preamble having a sequence of N repetitive pulses, or other short bursts of energy, with constant time delay. Alternatively, the preamble includes a sequence of N pseudo-random time delayed pulses or short bursts of energy.
(b) a Start Frame Delimiter used for marking the exact position of the beginning of the data. The Start Frame Delimiter is a sequence of symbols which are not found as a part of the preamble; thus finding the Start Frame Delimiter marks with high probability the beginning of the data.
(c) Data, used for payload or other functions known in digital communications
Methodology for fast acquisition of various models of data transmissions is well known (e.g. John J. Proakis, Digital Communications New York: McGraw-Hill, 1983, 1st ed., and 1989, 2nd ed.). In U.S. patent application 20020018514, “Method and system for fast acquisition of pulsed symbols”, Haynes Leonard S. et. al, disclose a method which takes advantage of unique separation between consecutive pulses in order to identify the transmitted symbol. In U.S. Pat. No. 5,687,169, “Full duplex UWB communication system and method” disclosed by Fullerton et. al (1997), a particular scheme of pulsed waveform communication is outlined, along with the synchronization principle.
A particular method for synchronization with low power consumption is outlined in US patent application 20030174048, “Method and system for performing distance measurement and direction finding using UWB transmissions”, disclose a dedicated RF circuit, separate from the receiver for the reception of pulses; the dedicated circuit identifies a particular signal that is transmitted, and then collects the power supply to the UWB (pulsed) receiver. Apart from the fact that two circuits are needed, there is no outline of how to save power while acquiring the pulsed waveform.
There is thus a need for, and it would be highly advantageous to have a method and a system, for fast impulse radio synchronization with low power consumption.
The following references are incorporated herein by reference as if fully set forth herein:    M. K. Simon, J. K. Omura, R. A. Scholtz, and B. A. Levitt, Spread Spectrum Communications. Rockville, Md.: Computer Sci., 1985    Ultra Wideband Communication: an idea whose time has come, L. Yang & G. B. Giannakis, IEEE Signal Processing Magazine, Nov. 2004.